Despite investor Carl Icahn’s proposal to spin PayPal off from its parent company, eBay announced plans to allocate “a disproportionate share” of investments to PayPal in 2014, focusing on developing PayPal “ubiquity,” mobile and connections between online and offline commerce.

Together, eBay and PayPal create “mutually reinforcing network effects,” eBay CEO John Donahoe declared during the company’s Q4 earnings call last week. Much of that reinforcement, he said, happens through mobile commerce, which totaled $22 billion and $27 billion in transaction volume for eBay and PayPal, respectively, in 2013.

The PayPal Media Network is well-positioned for marketers and advertisers because its reach connects mobile targeting and brick-and-mortar merchant relationships.

“Whether it’s a sale in the physical world, online or on mobile, being able to connect the dots all the way from discovery to awareness to, ‘I like it. I’m going to buy it,’ is really a big piece of our evolution,” David Chang, COO of the PayPal Media Network, told AdExchanger.

Bridging in-store and online data has been a constant thorn for marketers and eBay’s CEO admitted this is still a struggle the company faces.

PayPal Media Network, which evolved from origins as mobile ad network WHERE Ads before its acquisition in 2011 by eBay, has seen its mobile reach more than double, from 50 million to approximately 120 million. But the ability to measure audiences cross-channel clearly, definitively and without duplication is still a work in progress.

“The ability to tie identity across multiple channels is still a big problem no one has fully solved and that’s a general vision for where we’re headed,” Chang said. “In order to pull that off, you need data. You need reach. You need merchants to sign on board and technology partners in the ecosystem to play nicely with you.”

Chang said one area of focus for PayPal Media Network this year is enabling merchant partners to drive commerce on their own properties. He referenced a product that has yet to launch, but “if you think about the typical consumer experience, there is the time you spend on third-party sites like Pandora, Facebook or Accuweather.com, the time spent on an eBay owned-and-operated property and then the time spent on a specific merchant’s site, apps or emails, which is still relatively untouched inventory.”

Developing metrics will evolve to discover the ideal reach frequency and media mix such that marketers can determine sales revenue and better attribute by channel, said Ben Kneen, head of product strategy for PayPal Media Network. But there’s still a problem around unifying solutions from different vendors: “If I’m a marketer and I look at how I touch my consumers, I’m probably using a variety of partners and a lot of different systems that in no way speak to each other,” Kneen said.

Factoring in-store or mobile into the online equation is also altering the way publishers price and model their inventory.

“I think you’re starting to see people sell not only on an impression basis,” Kneen said. “I think Facebook’s really sort of led that in a lot of ways, where they sell their news feed on an engagement basis [or a vendor like] PlaceIQ … which has sort of a qualitative metric of connecting a digital experience with an in-store experience.”